Study On Simultaneous Determination Of 8 Categories Of Veterinary Drugs Residues In Aquatic Products By UPLC-MS/MS

This study is based on ultrasound-assisted QuEChERS pretreatment combined with ultra-high performance liquid chromatography tandem mass spectrometry（UPLC-MS/MS）.A method was established for the simultaneous detection of 69 veterinary drug residues in 8categories,including sulfonamides,quinolones,macrolides,tetracyclines,triphenylmethanes,amide alcohols,β-agonists and steroids,and the main research contents and results are as follows:1.Through the optimization of mobile phase and mass spectrometry parameters,the best instrument conditions were determined:BEH C₁₈ chromatographic column（50 mm×2.1 mm,1.7μm）was used,0.1%formic acid water-acetonitrile was used as the mobile phase.Taking carp as the research object and the recovery rate of 69 common veterinary drugs as the investigation index,the optimization conditions of ultrasound-assisted QuEChERS pretreatment method were determined:match 0.5 m L of 0.1 mol/L Na₂EDTA-Mcllvaine buffer solution（p H=4）with 8 m L acetonitrile as extraction reagent,and take 5 g anhydrous sodium sulfate as dehydrator,100 mg C₁₈ as purification agent,1 m L 0.1%acetonitrile formate solution（95/5,v/v）as redissolution reagent.2.Within the concentration range of 0.10～50.00μg/L,the R² value of the linear regression equation of 69 drugs was greater than 0.93,thus showing a good linear relationship.The detection limit of this method is 0.059～1.8μg/kg,the quantitative limit is 0.20～6.0μg/kg.The recovery rates of all compounds at three addition levels varies from 40.27%～118.67%.The RSDs of all compounds were 2%～15%（n=6）,which could be used as a preliminary screening method for the detection of multiple veterinary drug residues in the laboratory.3.Using the established rapid screening method for 69 kinds of veterinary drugs in aquatic products,the applicability of oyster,tilapia and shrimp were analyzed respectively,and the spiked recovery and precision were investigated.The results are as follows:the spiked recovery rate of oyster samples ranged from 36.00%to 117.67%,and the RSD ranged from 1%to 9%;the spiked recovery of tilapia samples ranged from 36.33%to 95.67%,and the RSDs ranged from 2%to 10%;the range of the spiked recovery of shrimp samples was40.33%～165.33%,and the RSD was 2%～14%.Using this method to detect the actual samples,it was found that no target drug was detected.Taking advantage of this method and the standard method to analyze and compare the content of enrofloxacin in positive samples at the same time,the relative difference was 1.1%,which was within a reasonable range.This method is suitable for rapid screening analysis of a large number of samples of aquatic products.The method is simple and swift in testing,with low investment.It is applicable for preliminary screening analysis of multi-component and multi-category veterinary drug residues in aquatic products.